There are three main theories on time: presentism, possibilism, and eternalism. This is the difference between the three:
Presentism: Only the present moment exists
Possiblism: Only the present moment exists and everything that has happened in the past
Eternalism: Every moment exists
Visually it looks like this:
Presentism entails that the future and past do not exist; possiblism entails that the present and past still exist and is therefore commonly referred to as the "growing block theory;" eternalism entails that all moments in time exist such that the universe can be viewed as an eternal block, and is therefore commonly referred to as the "block universe."
Eternalism is the dominant view in science. In Relativity and the Nature of Spacetime Vesselin Petkov drives the point, arguing about the unlikely possibility of possiblism:
I think the arguments against the growing block universe indicate that it is very unlikely that such a view will be an adequate representation of the world. On the other hand, all arguments against the four-dimentionalist view are based on the sole fact that we are aware of ourselves and the world only at the constantly changing moment 'now'. But this fact, as we saw in Chap. 3, has two logically possible interpretations, one of which is fully consistent with Minkowski's view. That is why the four-dimentionalist view is the most serious candidate for correctly representing the world." (p. 167)
I agree with the consensus. I think eternalism best fits the data and that would mean we are living in a block universe. The future of every single moment from our subjective perspectives in the spacetime block already exists and there's nothing we can do about it. I know this can be mind blowing and very difficult on the ego. We like to think of the future as a wide range of possibilities. Believing our futures to be locked into place may cause a mild to severe existential crisis. It requires a certain degree of philosophical investigation and knowledge to handle. But I do think that understanding this and seeing the universe this way has as much potential as a paradigm changer as did heliocentricism, evolution, and the end of libertarian free will.